Die structure



Patetd'sepy. v1922 2 SHEETS-SHEET l.

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"APPLlcAxpN FILED APR. 22, 1920. 1 428, 1 74, Patented Sept. 5, 1922.

2 SHEETS-SHEET 2.

-5 Il l 61 n sa Fig. a

se lnventorf John A. Lutfher Patented Sept. 5, 1922.

srare JOI-IN A. LUTHER, OF SCHENECTADY, NEW YORK.

DIE STRUCTURE.

Application led Ap1i122,

To all fte/0m t 'may concern:

Be it known that l, JOHN A. LUTHER, a citizen of. the United States, residing at Schenectady, in the county of Schenectady, State of New York, have invented certain new and useful improvements in Die Structures, of which the following` is a specification. v

The present invention relates to dies such` as are used with punch presses for punching' out or forming small articles from strips or plates of sheet material. ln connection with the manufacturing of certain articles onl punch presses it is necessary to make a largeA number of different sizes and this, asis obvious, requires an equal number of different' sized dies. F or example, in manufacturing washers it is necessary to be prepared to fur-j nish them in many sizes of both inside and outside diameters often differing fromreach" other by only a few hundredths of an inch and this means that there must be a die for every size. f

The object of my invention is to provide an improved structure and arrangementin a die whereby I am enabled to providel dies of various sizes in a very simple manner and at exceedingly low cost, it being possible to turn out the die parts by simple machine operations and without the services of highly skilled die makers.

For a consideration of what I believe to be novel and my invention, ,attention is directed to the accompanying description and the claims appended thereto. i

In the drawing, Fig. 1 is a sectional view of a die structure embodying my invention; Fig. 2 is an exploded view of the upper die parts; Fig. 8 is an exploded view of the lower die parts; Fig.' 4 is a perspective view of an article adapted to be made by the die structure shown in Fig. 1; Figo is a view similar to Fig. 1 of a modilication; Figs. 6 and 7 are exploded views of the upper andlower rdie parts respectively and Fig. 8 is a perspective view of an article adapted to beI made by the die structure shown in Fig. 5.,

Referring to Sheet lof the drawings,`104 indicates a shoe which is adapted to be mounted in the lower'part or member of a punch press as is well understood. At the center of shoe 10 is an opening 11 counterbored on its uppe'rside to form a recess in which is xed the flange 12 of an externally L threaded stud 18'." Stud 13 is perfectly made of' hard steel and it ifs shrunk into the recess 1920.y serial No. 375,833.v

in shoe 10 to make a tight fit. Supported on l the upper end of stud 13 isa combined punch and die 14. It is in the form'of a tube the upper or outer end having sharp cutting edges 15 and 16 and the lower or inner end beingl provided with a flange 17 which is clamped against stud 13 by a nut 18 which threads over stud 13 and has an annular shoulder which engages over flange 17. Projecting from nut 18 are a number of guide pins 19, for example three, which project through openings in and form guides for an annular reception plate 20. Reception plate 20 has an opening 21 at its center through which die 14 projects. Opening 21 is of greater diameter than die 14 and located between die 14 and the edge ofv opening 21A is a stripper plate 22 provided with a flange 23 which rests on reception plate 20. Stripper plate 22 acts as a guide forthe outer end of die 14. Reception 'plate 2O is prevented from separating entirely from nut 18 by a' suitable number of' holding screws 24, for example three, which pass lloosely through holes in nut 18 and thread linto* the underside of plate 20, the holes inv nut 18 being counterbored to receive the heads of screws 24.

Reception plate 20 rests on an ejector ring 25 which is connected bygposts 26 to a cross piece 27. Cross piece 27 ,is guided in its` which carries a nut 81 againstv which the vlower end of spring 30 rests. At 31b is aV lock nut 'for fastening bolt 3 7'1fin adjusted position. y c

The upward movementgof cross biece 27 and ring 25 is limited by an adjustable stop 82 in the form of a threaded bolt-adapted to be locked in adjusted position by a lock nutA 32a. Projecting through'stripper plate 22 is a stop pin 33 whichis yieldinglyl held in the position shown in Figs. 1 and 3 by a curved spring 84 vfastened to the underside of plate 22. It will bel seen that ring 25, posts 26, and cross piece 27 form an ejector frame which is yieldingly pressed against plate 20 by spring 30 and is'v limited in its upward movement by stop 82 and the heads of' bolts 24'.

The upper member ot the die structure comprises a holder 35 adapted to be tasteneu to the movable jaw ot a punch press, and provided with a central recess 36 to receive the head 37 or a combined punch and die 38. lier/'ess 36 is .counterbored to form a chamher 39 which surrounds die 38, and sliding or. die 38 is an ejector 40 havi'ire,I a head 41 which is located in chamber 39, Supported on the end ci holder 35 is a combined punch and die 42, the same having a rlange 43 which is clamped against the end ot holder by a llanged nut 44 which threads into the end ot holder The eiector 40 lits the annular space between dies and 42 and is adapted to slide therein. Extending through openings in holder 35 are a suitable number of ejector pins 45, for example three, which at their inner ends engage ejector head 41 and at their outer ends are fastened to pad 46.

ifi die structure as descr-il ed is adapted to ma re washers 47 as shown on an enlarged scale in Fig. 4 and the operation is as follows:

The upper and lower die members are placed iu the respective parts of a punch press which periodically brings them together and away :from each other, the die member standing at a sufficient angle ilo the. vertical. so the punched out parts will tall by gravity Yfrom between them. rlhe end of strip of material from which the washers are to bev punched is slid across the .lower die member until it comes into contact with stop pin 33n lllhen the die members come together .upper die 42 strikes stripper plate 22 and 'forces it and reception plate 2O downward against the action of the ector frame, the inner edge of die 43 co-operatingv with the outer edge 15 or die 14 to sever the strip orV material on the outer diameter or the washer. At the same time die 33 cri-operates with the inner cutting edge 16 of die 14 to punch out the center of the washer, such punched out center falling through the central opening or` die 14. The die 14 is ot the same size as the upper ejector 40 and tl e washer when punched out will be forced by die 14 up around the lowei` end or' die 38, die 14 projecting through the opening in the strip of material formed by the punched out washer. When the dies separate, the ejector frame is pushed upward by spring 30 toforce stripper plate 22 against the strip of material and remove it from die 14 so the operator may feed it ahead 'for another washer. rlloward the top of the stroke oit the upper die member', pad 46 strikes a lined abutment on the press which drives pins down against the head 41 of ejector 40 or the upper die thereby forcing ejector 40 downward to knock the washer oft' die 33.

lt will be noted that the upper and lower die structures are each builtup from a pluifi-asma rality of comparatively simple parts which can be easily made in various sizes and quickly (hanged to adapt the press for stamping out washers, in this particular instance, ot any sir/ie. For example, ii'.1 it is desired to stamp out washers ot a slightly greater or lesser outside diameter than that ior which the die members are new set up7 it is only necessary to change die 42 and ejector 4() in the upper die structure, and die 1 4 and stripper plate in the lower die structure. This can be quickly and easily done in the case oli the upper die member by removing nut 44, replacing the present die `i-2 and ejector 40 by similar parts of the required dimensions and replacing nut and in the oit the lower die member, by removing stripper plate unscrewing nut 1 3, saibstitutingl a new die 14 and stripper plate and clamping the new die in place by nut 13. ln a similar manner the die members can be changed tor punching out washers of various dimensions as is obvious.

connection with. the upper die structure, die is axially aligned and guided by ejector 40 and die 42 and as a result the only parts which need be accurately sized are the lower or outer end or dies 38, ejector 41 and die 42. These are all plane surfaces oit revolution. and are easily mace to exact di 'iensions and fitted. Head 37 or die 38 i ade to lit loosely in recess 36 and may be therein by a pin or other suitable means. This permits die 3S to readily align itself in ejector 40. also permits die 38 to be easily removed and replaced when changing' the die structure, and does not require the careful fitting o'l head 37 in recess 36. lis to the lower die structure, the only parts to be accurately sized are the punching or external end oli die 1T and the stripper plate 22 in which it is guided. rlie other parts need be fitted with only ordinary accuracy.

By the foregoing construction l obtain a die structure which while accurate is at the same time simple and cheap to build and readily changed to adapt it :tor many sizes.

Die structures embodying my invention may be made for stamping out and forming articles of various shapes and tor various uses, and on sheet two of the drawinfrs 1 have illustrated a die structure for stamping out an article olf the contour shown in llio. 8, i. e., ring, tion.

Referring to sheet two, 50 indicates shoe provided at its central portion with opening 51, which is counterbored to receive the flange 52 or an externally threaded stud 53. Stud has an axially extendifo' opening which aligns with opening 51 and it is counterbored to provide an annular shoulder 54 and a chamber 55. 56 is an annular' formll-shaped in cross secing tool having a head 56a which fits loosely in the-lower counterbore of stud 53 and rests on annular shoulder 54. Tool 56 is in the form of a tube provided with an internal shoulder 57 and extending through it is a rod 58 having a head 59 which rest-s on shoulder 57. 'Projecting from head 59 is a punching tool 60. Rod 58 projects through opening 5l in shoe 50 and its end is threaded to receive a nut 61 for 'fastening forming tool 56 and rod 58 to the shoe. Clamped on the end of stud 53 by a flanged nut 62 is an annular die 68 having an inner cutting edge 64, and between die 68 and the outer end of forming tool 56 is an ejector 65 provided with a flange 66 located in chamber 55. Bearing against flange 66 are a number of ejector pins 67, three for example, which extend out through openings in shoe 50 and are connected at their lower ends to a disk 68 against which bears4 one end of a spring 69, thev other end of which rests on a cross bar 70 carried by posts 7l depending from shoe 50. The tension of spring 69 may be adjusted by threaded bolt 72 in an obvious manner. Spring 69 serves to bias ejector 65 to the position shown in Fig.5.

The upper member of the die structure comprises a holder 75 having a central recess 76 which is counterbored to form a chamber 77. Fastened in recess 76 is the head 78 of a tubular inner die 7 9. Head 78y fits loosely in recess 76 and is hung therein by a pin 80. Die head 78 is counterbored from its upper inner end to form an internal shoulder 8l against which rests the head 82 of a center ejector 83. When head 82 is against shoulder 81, the lower or outer end of ejector 88 protrudes just 'beyond the end of die 79. Engaging head 82 of ejector 88 is a rod 84 which extends out through an axial opening in holder 75 and is connected to a pad 85. Surrounding die 79 and spaced therefrom is an outer die 86 having a flange 87 which rests against the end of holder 75 and is fastened thereon by a flanged nut 88 which threads onto the end .of holder 75. In the annular space between dies 79 and 86 is an ejector 89 having a head 90 located in chamber 77, and engaging head 90 on a suitable number oi ejector' pins 9i which extend out through holder 75 and are fastened to pad 85. Surrounding the lower end of die 86 is a compressor and stripper plate 92 which is fastened'in a holder 98 by screws 94. Holder 98 is supported by a suitable number of rods 95, for example three, which extend freely through open ings in nut 88 and have heads 96 resting on the nut. Surrounding each rod 95 between nut 88 and holder 98 is a spring 97. Holder 93 and stripper plate 92 are thus yieldingly held against upward movement. i

. As the best shown is Figs. 6 and7, die 79 has an inner cutting edgey 7 9a, the outer edge being cut back slightly, and die 86 has an outer cutting edge 86, the inner `edge being out back slightly. Cutting' edges 7 9a and 86a co-operate with the outer edge of'punch 60 and thecutting edge 64 of die 63 respectively. Forming tool 56 has rounded end.

The die members shown in Figs. 5, 6 and 7 are used in a punch press the same as those described in connection with Figs. l, 2 and 3, and when they come together with a sheet of material between them, an annulus is first cut out by edge 7 9a of die 79 and the outer edge of punch 60, andedges 86n and 64, and this annulus is then pressed down over the end of forming rtool 56 by the cut back edges oi dies 79 and 86 to form a structure as shown in Fig. 8. The strip of material from which the annulus is punched is pushed up around upper die 86 by lower die 68, stripper plate 92 being pushed upward against the action of springs 97 and the disk punched from the center oi' the annulus is pushed up inside die 79. ln forming the U-shaped ring of 1Eig. 8, dies 79 and 86 move beyond the end of forming `tool 56, die 86 pushing ejector 65 downward against the ac tion of spring 69. At the same time the end of forming tool 56 pushes ejector 89 upward. Now as the dies separate ejector 65 will push the U-shaped ring which has been formed off the end or" forming tool 56 and such ring will be carried upward between dies 79 and 86, while at the same time stripper plate 92 will push the strip of material from which the U-shaped ring has been formed, off die 86 soit will rest on the lower die member ready to be moved iorforming the'next U- shaped ring. At the top of its stroke, pad 85 strikes a stop on the punch press thereby pushing ejectors 83 and 89 downward to knock the punched out disk from out ythe center of die 79, and the U-shaped ring from between dies 79 and 86. y

It will be seen that they die members of Figs. 5, 6 and 7 are made up of separate con centric parts the same as the die members of Figs. l, 2 and 3, and these parts likewise need be exactly sized only at their outer ends. In connection with the lower die member the head 5660i die 56 may fit loosely in the counterbore of stud 53 and nut 6l need n-otbe particularly tight since the .outer end of die 56 is centered and guided by ejectork 65; and in the ,case of the upper die-1nember, the only parts to be closely fitted and l-lolder 93 is adapted to hold stripper plates hai/*ing various sizes of central openings and various sizes or' dies may be supported by holder 75.

lt will be seen 'from a consideration of my invention that l. am enabled to produce dies of many sizes from comparatively :tew parts and in a simple manner. @ne application of my invention is the making oit washers and gaskets for spark plugs, an application which requires he production of ni-'ny sizes often with but sli ght variations in sise. By my invention l am enabled to .reduce 'very materially the cost for dies. This is due primarily to the fact that 'there are 'Lew surfaces to be exactly sized and fitted to each other and in every case these are surfaces which are readily accessible and easily made to ein act dimensions. ln each die member here is an outer die whicn is rigidly fixed to a holder or carrier and other die parts which are loosely connected at their inner ends by the holder, and have their outer ends fitted and located within the outer die. This means that the inner die parts and the adjacent parts or the holder need not be eiractly sized and linished to each other. ln other words, the portions of the die parts which need bel exactly finished are limited to tie active working ends oi such parts.

ln accordance with the provisions or the patent statutes, l have described the principle of operation oli my invention, together with the apparatus which l now consider 'to represent the best embodiment there/oi?, but l desire to have it understood t t the apparatus shown is only illustrative and that the invention may be carried out by other means.

lWhat l vclaim as new and desire to secure by Letters Patent oli the United States, is

l. A die member comprisinga holder, and a plurality ot separate concentric parts carried thereby7 said parts being dimensioned and lit'ted together' at their outer ends with a ground lit so they serve to support one another in concentric relation at their outer ends whereby the inner ends need not be accurately dimensioned and lit-ted.

2. A die member comprising a holder, and a plurality of' separate concentric parts 'fastened to said holder at their inner ends and dimensioned and litted 'together at their outer ends, with a .Oround tit so they serve to support one another in concentric relation at their outer ends whereby the inner ends need not be accurately dimcnsioned and fitted together.

3. A. die member comprising a holder having a counterbored recess, a die having a head located in said recess7 a second die spaced from the .first die and fastened to the end of said holder, and an ejector which lits the space between the outer ends of said dies with a ground .fit whereby it sserves'to center and guide the outer end ot the .firstnanied die. Y

A die member comprising a holder having a centrally axially extending counterbored recess, a die having a head which loosely lits said recess, a second die, a nut which astens it to the end of said holder, and an ejector located in and fitting accurately the space between the outery ends of said dies with a ground lit whereby said.

second die and ejector serveito position and guide the lirstsnamed die.

ln a die structure, a holder, an outer die 'aed thereto, and other die parts carried by the holder and dimensioned yand fitted at their outer ends only tothe-inside ot said outer die with a ground lit, said outer die serving a guide and centering means for said other die parts.

G. ln a die structure, a holder having an axially extending recess at one end, an annular die detachably lined to such end of said holder, and die parts carried by'the holder' within said recess and detachably fastened thereto, said die parts being accurately dimensioned and fitted to each other with ground lits at their outerends and guided by said fixed die.

7. ln a die structure, a holder having a counterbored end, a die lined on such end, a second die loosely connected at its inner end to said holder andspaced from thein; ner surface of said iirstnamed die, an ejecltor accur tely fitted in the spacezbetween the outer ends oi said dies, witha `ground it, said second-named die and ejector being and guided at their outer ends by said first-named die, and ejector pins carried by said holder and engaging said ej ector.

8. ln a die structure, a holder having an axially extending counterbored .recess in one end., an annular die detachably iXed on snch end, a second die having its inner `end held in and accurately fitting Asaid recess, and an ejector' located in the annular space between saiddies with a ground fit, said ejector having a head located in the counterbored portion or said recess for limiting the outward movement of the ejector, and said ejector and second die being centered by said first-named die.

9. ln a die structure, a holder, a die detachably lixed to said holder, and a stripper surrounding said die and comprising an annular holding part carried by said holder and a second part detachably connected to said holding partand litted to said die, whereby said second part may be readily changed to conform to various sizes or' dies.

l0. ln a die structure, upper and lower die members each comprising a holder having a recess in one end, a die detachably ixed to such end, and die parts carried by llO` the holder in said recess, said die parts being centered by said die, and a stripper surrounding one of said dies and comprising a holding part and a second part detachably connected to said holding` part and fitted to the die which it surrounds.

ll. In a die structure, upper and lower die members, each comprising a holder having an axially extending counterbored recess, a die fixed on the end of said holder, and a second die having its inner end located in said recess and its outer end spaced from said die, and die parts comprising a forming die and ejectors which lit accurately the spaces between the dies of l5 each member with ground lits, said outer die in each case serving to center and guide said die parts.

In witness whereof l have hereunto set my hand this 17th day of April, 1920.

JOHN A. LUTHER. 

